Bordetella pertusis

• Bordetella Pertussis
• Guillaume de Baillou: 'The lung is so irritated that in its attempt by every effort to cast forth the cause of the trouble, it can neither admit breath or easily give it forth again. The sick person seems to swell up, and, as if about to strangle, holds his breath clinging in the midst of his jaws.'
• First used term pertussis

  Violent cough of any type
• Chinese term for cough

  Cough of 100 years
• Octave Gengou and Jules Bordet discovered the organism responsible for pertussis in 1900
• In 1906, media for isolation was developed
• Bordetella species

  • B. pertussis
  • B. parapertusis
  • B. bronchiseptica
• B. pertussis

  Affects only humans with no animal reservoir
• B. parapertusis

  Causes respiratory infections in sheep
• B. bronchiseptica


  Causes kennel cough in dogs and cats
• B. pertussis characteristics

  Gram negative coccobacilli<|>Strict aerobe<|>Possesses catalase activity<|>Does not ferment carbohydrates<|>Grows at 35-37 degrees Celsius<|>Fastidious
• Pathogenesis stages

  1. Transmission

  2. Attachment

  3. Evasion of host defenses

  4. Local damage

  5. Systemic manifestations
• Transmission

  Respiratory droplet infection
• 80-90% of non-immune siblings exposed in the household become infected
• 50% of non-immune contacts at school become infected
• Attachment factors

  Filamentous haemagglutinin<|>Fimbriae<|>Pertussis toxin
• Adenylate cyclase toxin


  Catalyses the conversion of ATP to cyclic adenosine monophosphate (cAMP)
• Pertussis toxin

  Important virulence factor for B. pertussis
• Local damage caused by

  Tracheal cytotoxin (TCT)<|>Dermonecrotic toxin
• Systemic symptoms are limited because the pathogen doesn't enter circulation
• Leukocytosis with predominant lymphocytosis is observed
• Pertussis toxin may cause encephalopathy
• Clinical presentation stages

  1. Catarrhal/prodromal stage

  2. Paroxysmal stage

  3. Convalescent stage
• Catarrhal/prodromal stage

  Begins after a 7-10 day incubation and lasts 1-2 weeks
• Paroxysmal stage

  Lasts 1-6 weeks, characterized by paroxysms or fits of cough
• Convalescent stage

  Lasts 1-6 weeks or longer, resolving symptoms
• Complications of Bordetella Pertussis


  • Pneumonia
  • Seizures
  • Paresis
  • Paraplegia
  • Blindness
  • Deafness
  • Aphasia
  • Urinary incontinence
  • Sub-conjunctival haemorrhage
• Bordetella Pertussis occurs worldwide and affects all ages
• Bordetella Pertussis is a major cause of death among malnourished populations
• Bordetella Pertussis is a major childhood illness and killer in the pre-vaccine era
• Morbidity rates are high within the first 2 years of life, mortality is highest in children under 1
• Maternal immunity is not complete for children
• Infection gives lifelong immunity to the infecting strain but not others
• Epidemics of Bordetella Pertussis occur in 4 yearly cycles
• Serotypes of B. pertussis

  • Three serotypes known to be pathogenic to man
  • Liable to spontaneous reversible variation
• It is impossible to investigate outbreaks using serology
• Genotyping methods perform better but are expensive
• High index of suspicion is needed for diagnosis
• Most diagnosis is clinical
• Confirmation requires a positive laboratory finding by culture or PCR